Apparatus for applying lubricant to a workpiece in a hot strip mill

ABSTRACT

A method and apparatus for applying lubricant to a workpiece in a four-high mill includes the application of an atomized lubricant to the back-up rolls from which it is transferred to the work rolls and then to the workpiece. A sensor detects when the workpiece enters and leaves the work rolls and actuates a control to automatically feed atomizing air and oil to nozzles directed toward the back-up rolls when the workpiece enters the work rolls and shut off the feed when the workpiece leaves the work rolls.

United States Patent 1191 11] 3,763 679 Lane et al. @ct. 9, 1973 [5 APPARATUS FOR APPLYING LUBRICANT 2,107,541 2/1938 Long 72/236 TO A WORKPIECE IN AHOT STRIP MILL 2,310,563 2/1943 Wilke I 2,707,098 4/1955 Turpin [75] Inventors: Wesley A. Lane, Provo, Utah; 3,064,509 11/1962 Ford et al. William G. Miller, Penn Hills 3,208,253 9/1965 Roberts Township, Allegheny County, Pa.; 3,523,437 8/1970 Bales et a1. Raha -t G, Whit y, Orem, U h 3,605,473 9/1971 Lyon et a1 72/201 [73] Assignee: United States Steel Corporation,

Pittsburgh, p Primary Examiner-Charles W. Lanham Assistant Examiner-E. M. Combs [22] Filed: 1971 Attrney-Donald S. Ferito [21] Appl. No.: 170,353

Related US. Application Data [57] ABSTRACT [63] x122 125 of 828931 May 1969 A method and apparatus for applying lubricant to a workpiece in a four-high mill includes the application 52 Cl of an atomized lubricant to the back-up rolls from 1 U S 6 3 which it is transferred to the work rolls and then to the [51] Int CL B2) 37/00 Bzlb /02 Bzlb 27/10 workpiece. A sensor detects when the workpiece en- [58] Field ofnsearch 72/41' 42 43 44 ters and leaves the work rolls and actuates a control to 72/45 l automatically feed atomizing air and oil to nozzles directed toward the back-up rolls when the workpiece [56] References Cited enters the work rolls and shut off the feed when the UNITED STATES PATENTS workpiece leaves the work rolls. v1,994,691 3/1935 Dahl et a1. 72/236 11 Claims, 5 Drawing Figures ATOM/2W6 111,? 82 74 Y 01L \PLUIVGE'R All? PAIENTEUum ems SHEET 2 [1F 3 FIG 3 IN VEW TORS WESLEY A. 1.4m; WILLIAM G. MILLER a ROBERT a. WHITNEY AffOl/ley APPARATUS FOR APPLYING LUBRICANT TO A WORKPIECE IN A HOT STRIP MILL This application is a continuation of application Ser. No. 828,931, filed May 29, 1969, now abandoned.

This invention relates to a method and apparatus for applying lubricant to a workpiece in a hot strip mill, and more particularly to a hot steel workpiece being reduced in a plurality of four-high mills. Various systems have been used to apply a lubricant to such workpieces, but none of which we have knowledge are entirely satisfactory. They do not provide a uniform distribution of the oil film on the workpiece. Also, they apply an excess of lubricant which remains on the mill rolls and must be removed before the next workpiece enters the rolls. This is normally done by stopping the flow of lubricant while the workpiece is still in the roll so that the heat from the tail end of the workpiece will burn off the excess lubricant. Thus, part of the workpiece is reduced without lubrication which results in less reduction and a non-uniform gauge throughout the length of the strip. Often the strip has an excessive crown. I

It is therefore an object of our invention to provide a method of hot rolling a workpiece in which the lubricant is present throughout the rolling operation.

Another object is to provide apparatus suitable for carrying out our method.

Still another object is to provide such apparatus which provides a thin uniform film of lubricant to the workpiece throughout its length.

A further object is to provide such apparatus which reduces the crown in the hot rolled strip.

A still further object is to provide such apparatus which reduces the roll wear per ton of strip rolled.

These and other objects will be more apparent after referring to the following specification and attached drawings, in which:

FIG. 1 is a schematic view of a rolling mill and the lubricating system of our invention;

FIG. 2 is a view ofa header adjacent a rolling mill roll without the atomizing spray nozzles mounted thereon;

FIG. 3 is a view taken on the line III-III of FIG. 2 with an atomizing nozzle mounted on the header;

FIG. 4 is an enlarged sectional view of an atomizing nozzle used in our invention; and

of our invention.

Referring more particularly to FIG. 1 of the drawings, reference numeral 1 indicates a first finishing stand of a hot strip mill and the reference numeral 2 indicates the second stand of a second finishing stand. Both roll stands are four-high mills and each has a top back-up roll 4, a top work roll 6, a bottom work roll 8 and a bottom back-up roll 12, all supported in roll housing 14. The workpiece or strip S passes through the work rolls of stand 1 and then through the work rolls of stand 2. All of the above is conventional.

According to our invention we provide headers 16 and 18 adjacent the top of rolls 4 and headers 20 and 22 adjacent the bottom of the bottom rolls 12. The headers 16, 18, 20 and 22 are identical so that only one will be described in detail. The headers extend transversely across the width of the roll and each has a body 24 with four openings 26, 28, 30 and 32 therethrough. A plurality of spray nozzles 34 are attached to the block 24 in any suitable manner such as by means of a bolt 36. As shown in FIG. 4 the spray nozzle 34, which may be a l/4 JAU Model of Spray Systems, Inc., includes a central opening 37 for receiving a lubricant and an air nozzle 38 for atomizing air. A clean out and shut off needle 40 is received in the opening 37 and has a piston 42 attached thereto which is urged by spring 44 to the closed position and is moved to an open position by means of air introduced through opening 46. The lubricant is introduced into the opening 37 from opening 26 through a side outlet 48 and atomizing air is introduced into the nozzle 38 through side outlet 50. Air for moving the piston 42 is introduced into nozzle 34 from opening 30 through side outlet 52. Steam is applied to the opening 32 to maintain the temperature of the lubricant constant.

Lubricant from a tank 54 is pumped by pump 56 through a conduit 58 to the header 16 and unused lubricant is returned from the header 16 to the tank 54 through a conduit 59. In like manner lubricant is fed through a conduit 60 to header 118 and returned to tank 54 through conduit 61. In like manner oil is delivered through conduit 62 to header 20 and returned through conduit 63. Lubricant is delivered through conduit 64 to header 22 and returned through conduit 65. The flow of oil to the headers is individually regulated by means of precision valves 66, 68, and 72 located in conduits 58, 62, 60 and 64, respectively.

Atomizing air is delivered to headers 16 and 20 through a conduit 74 having pressure regulator 76, pressure gauge 78 and a normally closed solenoid valve 80 therein. In like manner atomizing air is introduced to headers 18 and 22 through conduit 82 having pressure regulator 84, pressure gauge 86, and a normally closed solenoid valve 88 therein.

Air for operating the shut off needles 40 is delivered to headers 16 and 20 through conduit 90 having a pressure regulator 91, pressure gauge 92, and a normally closed solenoid valve 93 therein. In like manner plunger air is introduced to headers 18 and 22 through a conduit 94 having pressure regulator 95, pressure gauge 96 and solenoid valve 97 therein.

A transducer 98, such as a pressductor or load cell is mounted on the housing of stand No. 1. As shown in FIG. 5 the output of transducer 98 is connected through an amplifier 100 to relay coil 102 having a normally open contact 102C. Contact 102C is connected across power lines L1, L2 in series with parallel connected solenoids 80S and 93A which operates valves 80 and 93, respectively. The transducer 98 acts as a sensor to detect when the strip S enters and leaves Stand No. l. A similar transducer 104 is mounted on the housing of Stand 2 and its output is connected through amplifier 106 to relay coil 108 having a normally open contact 108C. Contact 108C is connected across lines L1, L2 in series with solenoids 88S and 97S which are connected in parallel. Solenoids 88S and 97S operate valves 88 and 97, respectively. An on-off switch 110 controls flow of current to the circuits across lines L1, L2.

In operation, the valves 66, 68, 70 and 72 are set to apply the precise amount of oil required on each roll. The oil output of the nozzles 34 is proportional to the header pressure which is regulated by these valves. The atomizing air is operated at a higher pressure than the oil and the pressure is regulated by means of pressure regulators 76 and 84 to provide the best pressure for atomization of the oil. The lubricant may be any standard lubricant used in hot rolling but is preferably oil having a viscosity between 500 S.U.S. at 100F. and 50 S.U.S. at 210F. The temperature of the oil is kept relatively constant by keeping the tank 54 heated, and by supplying steam to the headers and/or to the oil lines. The pressure of the plunger air is controlled by means of pressure regulators 91 and 95 to the pressure most suitable for the atomizer. The mill is ready for rolling as soon as the switch 110 is closed. As the workpiece S enters mill stand 1 the sensor 98 energizes relay coil 102 to close its contact 102C. This energizes solenoids 80S and 93S so as to open the valves 80 and 93. Opening of valve 80 causes atomizing air to flow through the headers 16 and to the atomizing nozzles 34.

Opening of valve 93 causes plunger air to move the shut-off needle to its open position against the pressure of spring 44. In like manner when the workpiece S enters stand 2 detector 104 will energize relay coil 108 to close its contact 108C, thus energizing solenoids 88S and 978 to open valves 88 and 97, thus delivering atomizing and plunger air to the nozzles 34 in headers 18 and 22. Thus, lubricant in the form of a uniform mist of oil is delivered to the rolls 4 and 12 and picked up by rolls 6 and 8 to cause lubrication between the strip S and the work rolls 6 and 8 of both stands. When the tail end of the strip S leaves stand 1 the sensor 98 is deenergized so that the contact 102C opens to deenergize solenoids 80S and 935, thus shutting off flow of atomizing air and plunger air. This permits spring 44 to move the shut off needle 40 to closed position with its clean out end 40C cleaning out the orifice. In like manner when the tail end of strip S leaves stand 2, sensor 104 is deenergized to open contact 108C so as to deenergize solenoids 88S and 97S and shut off flow of atomizing air and pressure air to the atomizing nozzles associated with headers 18 and 22. Wiper 4W associated with the upper roll 4 and wipers 12W on each side of the headers associated with the lower roll 12 limits cooling water carry over on the back-up rolls and thus results in substantially 100 percent concentration of the oil on the rolls. Because of the fine control of oil application which prevents an excess amount of lubricant on the work rolls 6 and 8 it is not necessary to burn off the lubricant from the work rolls. Further slippage reduction is obtained by providing the work roll with a coarser finish than normal. It will be understood that more than two roll stands may be provided with each roll stand being equipped in the same manner as the first two stands. If desired, to lubricate only one surface of the strip, this can be done by shutting off flow of lubricant to the headers on the opposite side of the strip.

While one embodiment of our invention has been shown and described, it will be apparent that other adaptations and modifications may be made.

We claim:

1. Apparatus for applying lubricant to a roll of a mill for rolling a metal workpiece which comprises a plurality of spray nozzles arranged across the width of said roll and directed toward said roll, each of said spray nozzles including an elongated opening for receiving lubricant and delivering it from the exit end of said spray nozzle, an air nozzle surrounding said opening for delivering air to atomize said lubricant and flow control means in said opening for shutting off and permitting flow of oil from said spray nozzle, and control means for operating said flow control means to cause flow of lubricant from said spray nozzle when the workpiece reaches said mill and shutting off said flow of lubricant when the workpiece leaves said mill.

2. Apparatus according to claim 1 in which said mill is a four-high mill having two work rolls and two backup rolls, and said roll is one of the back-up rolls.

3. Apparatus according to claim 2 in which an atomizing air conduit means is connected with said nozzles for delivering atomizing air thereto, and said control means includes a solenoid valve in the atomizing air conduit means, a sensor for detecting presence of the workpiece in said four-high mill, and a control circuit operable by said sensor to open said solenoid valve when a workpiece is in said mill and to close said solenoid valve when the workpiece leaves said mill.

4. Apparatus according to claim 2 including a lubricant supply header adjacent the top of the top back-up roll and extending across the width thereof, a lubricant supply header adjacent the bottom of the bottom back-up roll and extending across the width thereof, a lubricant storage means, a plurality of said spray nozzles being connected to each supply header, a separate oil supply conduit leading from said storage means to each header, a closed return conduit means between said headers and said storage means, and means for continuously circulating lubricant from said storage means through said feed conduit means, said headers and back to said storage means when the mill is in operation.

5. Apparatus according to claim 2 in which said flow control means is a shut off needle, and a fluid operated cylinder for moving said needle; and in which said apparatus includes conduit means for supplying fluid to said cylinder.

6. Apparatus according to claim 5 in which an atomizing air conduit means is connected with said nozzles for delivering atomizing air thereto, and said control means includes a solenoid valve in the atomizing air conduit means, a solenoid valve in said fluid conduit means, a sensor for detecting presence of the workpiece in said four-high mill, and a control circuit operable by said sensor to operate said solenoid valves to permit flow of atomizing air to said air nozzle to open said shut off needle when a workpiece is in said mill and to shut off flow of atomizing air to said air nozzle and to close said shut off needle when the workpiece leaves said mill.

7. Apparatus according to claim 6 including a lubricant supply header adjacent the top of the top back-up roll extending across the width thereof, a lubricant supply header adjacent the bottom of the bottom back-up roll extending across the width therof, a plurality of said spray nozzles being connected to each supply header, a separate oil supply conduit leading to each header and a control valve in each of said oil supply conduits.

8. Apparatus according to claim 7 in which said atomizing air conduit means includes a conduit leading to each header and said fluid conduit means includes a conduit leading to each header.

9. Apparatus according to claim 8 including lubricant storage means, return conduit means between said headers and said storage means, and means for continuously circulating lubricant from said storage means through said feed conduit means, said headers and back to said storage means in a closed system when said mill is operating.

lating lubricant from said storage means through said oil supply conduit, said header and back through said return conduit to said storage means when the mill is in operation.

11. Apparatus according to claim 2 in which said work roll has a coarse finish.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3; 7 3, 79 Dated October 9, 1973 Inventor) Wesley A Lane, et a1.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line LLT, "93A" should re d 9 Signed and sealed this 2nd day of April 19%.

(SEAL) Attest:

EDWARD I'LFLETCHERJR. C. MARSHALL DANN Attesting Officer Commissioner of Patents ORM 5 (m'sg) uscoMM-Dc 60376-P69 U.S. GOVERNMENT PRINTING OFFICE: 1969 0-366-33A, 

1. Apparatus for applying lubricant to a roll of a mill for rolling a metal workpiece which comprises a plurality of spray nozzles arranged across the width of said roll and directed toward said roll, each of said spray nozzles including an elongated opening for receiving lubricant and delivering it from the exit end of said spray nozzle, an air nozzle surrounding said opening for delivering air to atomize said lubricant and flow control means in said opening for shutting off and permitting flow of oil from said spray nozzle, and control means for operating said flow control means to cause flow of lubricant from said spray nozzle when the workpiece reaches said mill and shutting off said flow Of lubricant when the workpiece leaves said mill.
 2. Apparatus according to claim 1 in which said mill is a four-high mill having two work rolls and two back-up rolls, and said roll is one of the back-up rolls.
 3. Apparatus according to claim 2 in which an atomizing air conduit means is connected with said nozzles for delivering atomizing air thereto, and said control means includes a solenoid valve in the atomizing air conduit means, a sensor for detecting presence of the workpiece in said four-high mill, and a control circuit operable by said sensor to open said solenoid valve when a workpiece is in said mill and to close said solenoid valve when the workpiece leaves said mill.
 4. Apparatus according to claim 2 including a lubricant supply header adjacent the top of the top back-up roll and extending across the width thereof, a lubricant supply header adjacent the bottom of the bottom back-up roll and extending across the width thereof, a lubricant storage means, a plurality of said spray nozzles being connected to each supply header, a separate oil supply conduit leading from said storage means to each header, a closed return conduit means between said headers and said storage means, and means for continuously circulating lubricant from said storage means through said feed conduit means, said headers and back to said storage means when the mill is in operation.
 5. Apparatus according to claim 2 in which said flow control means is a shut off needle, and a fluid operated cylinder for moving said needle; and in which said apparatus includes conduit means for supplying fluid to said cylinder.
 6. Apparatus according to claim 5 in which an atomizing air conduit means is connected with said nozzles for delivering atomizing air thereto, and said control means includes a solenoid valve in the atomizing air conduit means, a solenoid valve in said fluid conduit means, a sensor for detecting presence of the workpiece in said four-high mill, and a control circuit operable by said sensor to operate said solenoid valves to permit flow of atomizing air to said air nozzle to open said shut off needle when a workpiece is in said mill and to shut off flow of atomizing air to said air nozzle and to close said shut off needle when the workpiece leaves said mill.
 7. Apparatus according to claim 6 including a lubricant supply header adjacent the top of the top back-up roll extending across the width thereof, a lubricant supply header adjacent the bottom of the bottom back-up roll extending across the width therof, a plurality of said spray nozzles being connected to each supply header, a separate oil supply conduit leading to each header and a control valve in each of said oil supply conduits.
 8. Apparatus according to claim 7 in which said atomizing air conduit means includes a conduit leading to each header and said fluid conduit means includes a conduit leading to each header.
 9. Apparatus according to claim 8 including lubricant storage means, return conduit means between said headers and said storage means, and means for continuously circulating lubricant from said storage means through said feed conduit means, said headers and back to said storage means in a closed system when said mill is operating.
 10. Apparatus according to claim 9 including a lubricant supply header extending across the width of said roll, said spray nozzles being connected to said supply header lubricant storage means, an oil supply conduit leading to said header from said storage means, a closed return conduit means between said header and said storage means, and means for continuously circulating lubricant from said storage means through said oil supply conduit, said header and back through said return conduit to said storage means when the mill is in operation.
 11. Apparatus according to claim 2 in which said work roll has a coarse finish. 